Transmission mechanism



June 3, 1942. w WESTQN TRANSMISSION MECHANISM Filed Aug. 10, 1938 5Sheets-Sheet 1 INVENTOR iFoy M 14/22:; 7-0/7 June 30, 1942. R. w. WESTONTRANSMISSION MECHANISM Filed Aug. 10, 1958 5 Sheets-Sheet 4 June 3?),1942. w WESTON 2,288,057

TRANSMISSION MECHANISM Filed Aug. 10, 1938 5 Sheets-Sheet 5 PatentedJune 30, 1942 UNITED STATES PATENT OFFICE TRANSMISSION MECHANISM Roy w.Weston, Flint, Mich. Application August 10, 1938, Serial a... 224,169Claims. (01. 74-1895) This invention relates to transmissions of thetype used in automotive vehicles.

Transmissions used on automotive vehicles have shifting and furtherbecause-of the inherent possibility of uneven change in speed broughtabout by the step-by-step type of gear ratio mechanism,

it has long been considered a-possible refinement of design to provide atransmission which would produce a uniform smooth change in gear ratiowithout provision of steps. Such a mechanism would provide in reality aninfinite number of steps to produce a smooth continuous change of ratio.However, many of such mechanisms designed in the past have been ofcumbersome mechanical construction or so complicated as to beprohibitive in price.

With the present trend toward the use of automatic transmissions it isimportant that any transmission be particularly adaptable for automaticoperation so that little or no manual skill of the driver is required toproduce the required changes in gear ratio.

It is, therefore, a primary object of the present invention to provide atransmission of practical design which will be capable of varying theratio between the engine and the driving wheels of the vehicle in acontinuous change from the highest gear ratio to a direct drive oroverdriveratio without step-by-step gear changes.

It is a further object to provide a transmission design providing forcontinuous change in gear ratio which is of a size and constructioneasily adaptable for use in automotive vehicles.

It is another object to provide a transmission mechanism particularlyadaptable for automatic operation.

It is a further object to provide a transmission mechanism employing adifferential gear unit controlled by fluid pressure operated means.

It is a further object to provide control mechanism for a transmissionby control of the relative rotative speed of two rotating shafts by theprovision of fluid displacing mechanism controlled is but taken on theopposite side of theunit from g by the operation of a fluid pressureoperated mechanism.

The above and other objects of the invention will appear more fully fromthe following more detailed description and vby reference to the accompanying drawings forming a part hereof and wherein: I

Fig. 1 is a cross section through the transmission housing showing thegeneral arrangement of the several parts of the mechanism.

Fig. 2 is a section taken substantially on the line 2-2 of Fig. l andshows the several cylinders and pistons of a hydraulic pump or fluiddisplacing mechanism.

Fig. 3 is a section taken on the line 3--3 of Fig. l and shows thatportion of the fly-wheel in which the pump shown in Fig. 2 is housed.

Fig. 4 is a section on the line 4-4- of Fig. 1 and shows the severaloutlets for the hydraulic pump 01' fluid displacing mechanismhoused" inthe flywheel and also shows the gear mechanism to assure the properalignment of the pistonsand cyl inders of the hydraulicpump. Y e

Fig. '5 is a section on the line' 5 5 0f;Fl gZ; 1-

and shows the difierential gear unit,' which'is an important part of thetransmission;mechanism;' the difire'n Fig.6 is-a viewof the ho'u'singfortial gear unit shown in Fig. 5.

Fig. 7 shows a viewer-the control mechanism for the transmission asmountedfon'a: panelrat the side of the transmission housing.

Fig. 8 is another view of the unit shown'in Fi'g I 7 taken from the topthereof. Fig. 9 is a view of the units shown inFigs. land the view shownin Fig. 8. I

Fig. 10 is a view of the eccentric yoke for holding the hydraulic unitring in position for opera tion and for varying the eccentricity of thesame to change the ratio of the transmission.

Fig. 11 is a section through the control cylinder for operating thehydraulic motor yoke shown in Fig. 10.

Fig. 12 is a section taken on line l2|2 of Fig.

Fig. 1, wherein the several parts'of the transmission are shownsupported in a housing 2| positioned at the rear end of the engine ofthe vehicle. The most forward positioned rotating part of thetransmission is a fly-wheel 22, which may be of substantially the samediameter as the conventlonal fly-wheel now used and may have combinedtherewith a starter gear 25, the flywheel 22 being mounted to be rotatedby the crankshaft 23 of the engine. In this case, however, the flywheelhousing 22 is of such interior construction as to house an hydraulicpumping unit, composed of a plurality of pistons 24 and cylinders 26. Inthe unit used for illustration there are six of these cylinder andpiston units positioned radially in the circular fly-wheel, thecylinders 26 being plvotally mounted on pins 21 and the pistons 24 beingconnected to the circumference of a crank bearing 28 by means of pins29. The crank bearing 28 surrounds a crank 3|, which crank is secured torotate with a shaft 32. The

crank shown is of two part construction being split at 3|a for purposeof facilitating assembly of the unit.

The fly-wheel housing 22 as shown in Fig. 1 has a cone shaped endextension 33, which is secured to a sleeve member 34, which surroundsthe aforementioned shaft 32, the sleeve 34 serving as the input shaft ofthe transmission. Connection between the fly-wheel extension 33 andamount of rotation will be controlled in proportion to the amount ofsuch flow.

For the purpose'of carrying out the idea of controlling the relativerotation by control of fluid flow as above outlined, an hydraulic orfluid operated unit 31 is provided for receiving and regulating thefluid allowed to be displaced by the pumping unit in the flywheel. Theunit illustrated in the drawings comprises a plurality of pistons andcylinders 38, 39 mounted to be carried by rotation of input sleeveshaft'34and fly-wheel 22. The arrangement of the cylinder and pistonunits is best understood by consideration of Figs. 1 and 16 wherein itappears that is splined on the sleeve 34 and bolted or otherwise securedto the hydraulic cylinder and piston units. Over the major portion ofthe length oi! the hydraulic operated unit a sleeve 42 is interposedbetween the sleeve-34 and the hydraulic operated unit, this sleeve beingsecured to the housing 2| by a plurality of bolts shown at 43, aconstruction which will be evident on inspection of Fig. 1.

As shown in Fig. 1, each of the cylinder and pistonunits is made up of apair of opposed cylinder and piston units 38 and 39, each of the twocylinders facing'each' other and with short pistons positioned so thattheir semispherical ends 44 and 46 contact a V-shaped rethe input sleeveshaft, 34 is effected by means of bolts 36.

For the purpose of keeping the crank'3| in proper alignment with thecylinder and piston units 24, 26 a gear 26 is secured to the shaft 32adjacent the crank 3|. This gear is eccentric with the center of thecrank 3| and on rotation of the crank this gear meshes with a gear 260mounted to rotate with the crank and also meshes with a' gear 26bmounted to rotate with the cylinder and piston units. The constructionis shown in Figs. 1 and 4 and it is apparent that because of the meshingof the three gears the relative position of the crank and the cylinderand piston units will remain the same, and therefore no misalignment ofthese units will be possible, altholmh the flywheel and input shaftsleeve 34 may rotate at a different rate than the crank 3| and shaft 32to which it is attached.

It will be understood from the above description and by reference toFigs. 1 and 3 that the cylinder and piston units in the fly-wheel whichhave been generally referred to as an hydraulic pump, serveas a means ofconnection between the fly-wheel which is driven by the engine of thevehicle and the crank 3| which drives the shaft 32. Although thecylinder and piston unit is described as a pump or displacing unit, itreally controls the connection between the two aforementioned rotatingmembers and allows relative rotation between them in an amountproportional to the displacecment allowed to be made by the pumpingunit. In other words, if the fluid is not allowed to flow from the unit,it will result in locking of the fly-wheel with the crank, and requirethat these two parts turn at the same rate of speed. However, if acertain amount of flow is allowed, the relative action ring 46positioned between the opposed pistons.

Fluid under pressure which actuates the hy-- draulic motor unit iscarried from the fluid displacing pistons 24, 26 by a conduit 41extending from the end of each cylinder 26 through the cone shapedflywheel extension 33, two of these conduits being shown in section inFig. 1. The coneshaped extension is so shaped relative to the conduitsand these conduits are so ter- .minated as to register with inletconduits 49 and outlet conduits 6|, there being three conduits 49positioned at equal distances around the semi-circumference of thebearing surface 62 and threeloutlet conduits around the othersemicircumference of the bearing 62. The three inlet conduits 49 connectwith three passages 63 in the sleeve 34, each of which passages opensinto a chamber 64 in each of the plurality of cylinderand piston units38, 39. Each chamber 64 has outlets at both of its ends 66, 61, one ofwhich leads into the cylinder of a cylinder and piston held instationary position, that the action of I the plurality of cylinder andpiston units 24, 26 will be to force fluid under pressure into and outof the chamber 64 of the cylinder and piston units of the hydraulicunit. Furthermore, because of the fact that half of the cylinder andpiston units 24, 26 are connected with an inlet conduit. while the otherhalf are connected to outlet conduits, it becomes apparent that-theplurality of circumferentially positioned cylinder and piston units 38,39 will be successively sub- Jected to pressure as the unit rotates. Itfollows from the above that the plurality of units will speed ofrotation of this carrier and the speed of rotation of the gear 58 andthe hydraulic operated unit which rotates it. And considering thecentral gear unit as a differential gear unit, it will be apparent thatas the car picks up speed the gear ratio will gradually decrease.Furthermore, if a control is worked out which will automatically changethe position of the reaction ring 46 with this increasing speed theresult will be a gradual change in gear ratio from the highest gearratio to the one-to-one or "high gear ratio.

It is noted that the device provides change in gear ratio by control ofthe relative rate of rotation between the differential spider member 59and the input shaft sleeve 34 with its attached differential gear 58.The plurality of cylinder and piston units 24, 26, located in theflywheel, simply act as a fluid displacing mechanism and in realityserve as a fluid connection between the differential spider 59 and theinput sleeve shaft 34. The amount of the displacement allowed by actionof the piston units is determined by the control of the hydraulic orfluid operated unit with opposed pistons and cylinders 38, 39. Aspreviously noted any eccentricity of the reaction ring 46 allows acertain amount of displacement of fluid from the cylin der and pistonunits. When this eccentricity is a maximum there is a maximum difierencein rate of rotation between the spider member and the differential gear58 and the highest gear ratio is afforded for starting the car. whenthere is, no eccentricity of the reaction ring 46 no displacement offluid is allowed and the differential spider member 59 and thedifferential gear 58 are forced to rotate at the same speed, therebycarrying the entire differential unit around as a unitand effecting aone-to-one ratio for the transmission. Intermediate ratios are obtainedby intermediate amounts of eccentricity of the reaction ring 46;thereby'allowing some displacement and movement of the piston membersand, therefore, some relative movement between the difierential gear 58and the spider member 59. Although it may be stated that the hydraulicor fluid operated unit is operated by the fluid displaced by theplurality of pistons mounted in the flywheel it is also true that theamount of displacement or operation allowed forthe hydraulic motorcontrols the amount of displacement which is allowed to be produced bythe cylinder and piston units so in reality the hydraulic unit controlsthe fluid displacing mechanism in the flywheel, or rather allows it tooperate a specified amount. In this way the relative rate of rotationbetween the shaft which is connected to the spider member and the inputshaft sleeve is controlled.

Control mechanism In order to actuate and control the operation of thetransmission described above it is necessary to provide means: (1) tochange the eccen- However,

tricity of reaction ring 46; (2) to actuate band 83 to effect reversedrive; (3) to actuate clutch p ates I9. These three controls must beactuated i proper relation to each other and in the mechanism heredisclosed fluid under pressure is used as the actuating medium. Theseveral fluid pressure control units are directly actuated by action offluid under pressure in suitably positioned cylinder and piston units. Apump driven from the transmission maintains a predetermined pressure ina system to which the several actuating units are attached.

' In order that the transmission mechanism be automatically operated thepiston unit controlling the reaction ring 46 is placed under the controlof a governor rotated from the transmission and the action of thisgovernor on the control mechanism is also modified by the throttleposition. It can therefore be said that rotative speed and throttlemovement both have'some determining effect on the gear ratio afforded bythe transmission.

With the above outline of the general scheme of control as a basis, theunits will be considered in more detail below.

Referring to Figs. 7, 8 and 9, there are shown three different views ofthe mechanism which isused to control the operation of the transmission.This mechanism is mounted on a plate I00, which as shown in Fig. 5 ismounted on the side of the housing-2L. A gear and shaft unit IOI has aspiral gear I02 mounted at the end thereof, this shaft IOI projectinginwardly from the plate I00 on which it is mounted. As shown in Fig. 1the gear I02 meshes with the gear I03 so that the shaft IOI is rotatedfrom the rotating parts of the transmission. The shaft IOI extendsthrough the plate I00 as shown best in Fig. 9 to an oil pump I04. Inaddition there is a second spiral gear I06 also mounted on the shaftIOI, which gear drives a governor shaft I01 through a gear I08 (seeFigs. 7 and 8). The

governor I09 is mounted for rotation at the end of the shaft I01. I

-'I'he above described shaft and gearing provides means to rotate theoil pump I04 and governor I09 from the transmission. It is considered ofimportance that the connection through gear I03 is such that thegovernor and oil pump are driven at a reduced speed when thetransmission is running idle through the reverse gears I2 which meshwith internal gear I03a to drive gears I03 and I02 (Fig. 1). It is notedthat reduction through the reverse gearing occurs only when clutch I9 isreleased, the gears I03and I03a being carried with housing I0 whenclutch I9 is engaged for forward driving. The reduction also occurs whenthe reverse gearing is actuated by contraction of member 83. Bypositioning the governor and oil pump drive as above described suitabledrive of the oil pump for idling conditions is assured, as well as forsuch special conditions as towing the car, etc.

Fig. 10 shows a mounting for a yoke III, which is of substantiallysemi-circular shape and of such diameter as to fit on the outside of abearing 2,, which is shown in Fig. 1 as mounted on the reaction ring 46previously described. It is the movement of this yoke III which controlsthe eccentricity of the reaction ring 46 relative to the axis ofrotation of the hydraulic motor unit 31. An assembly view of the yokeIII with a cylinder and piston unit H3 is shown in Fig. 9, the detailsof the cylinder, and piston unit being shown more completely in Figs. 11and 12.

have their pistons successively actuated so that. the semi-sphericalends thereof will react against crank 3| and shaft 32 will be forced torotate at the same rate as flywheel 22 and sleeve shaft 34, the fluid inthe conduits and cylinders simply serving as a connection. However, ifthe reaction ring 46 is moved to a position eccentricto the axis ofrotation of the unit, the pistons 38, 39

of the plurality of cylinders will be allowed to move successively asthe unit rotates and allow a certain amount of displacement of fluidinto and out. of the fluid operated unit. Such an allowed displacementin the fluid operated unit obviously will allow the pumping units 24, 26to move and thereby allow relative movement between the crank 3|, andflywheel 22. It is'obvious that the amount of this allowed displacementand consequent allowed relative movement will vary in proportion to theamount of eccentricity of the ring 46. Means to control thiseccentricity is described hereinafter.

A differential gear unit is positioned in the central portion of thehousing 2| and by its construction and arrangement provides means toeffect change in mechanical. advantage, or so called gear ratio, betweenthe input and output shafts of the transmission. A differential gear 58is secured to the end of the sleeve shaft 34, this sleeve 34 beingconnected to rotate with the flywheel 22 might therefore be termed aninput shaft of the transmission. A second differential gear 64 issecured to rotate with shaft 66 which might be termed an output shaft.Gearing which connects the two differential gears 58 and 64 is mountedon a carrier or spider 59 which is secured to rotate with the previouslymentioned shaft 32 which it will be remembered is connected with thecrank 3|. The spider 59 has a plurality of planetary gears mountedthereon. One set of three of these gears, 6|, are equally spaced andmounted to rotate on spider 59 and mesh with differential gear 58. Asecond set of three planetary gears 63 are here shown as integral withgears 6| and mounted on a shaft 62 carried by spider 59. These lastmentioned gears 63 mesh with the second differential gear 64. The gearpairs GI and 63 act as differential pinion 'gear but in this case are ofsuitable relative pitch diameters to provide a desired gear ratiobetween the inputand output shaft which will of course be varied by thedifferential rotation of the spider and the differential gears. As willlater appear the gear ratio is controlled by control of the relativerotation of spider 59 and differential gear 58.

Also mounted on each shaft 62 is a third set of three planetary gears 68which are secured to rotate with the gears 6| and 63 and to mesh with agear 68 which is secured to a sleeve 61. The

opposite end of the sleeve 61 terminates in a l2 meshing with a gear 16,which is splined to in one direction and will'be held against rotationif it attempts to rotate in the opposite direction.

For the purpose of effecting reverse drive of the transmission two setsof planetary gears I2 and 13 are carried by a spider 14, the set ofgears the shaft 86, and the set of gears 13 meshing with an internalgear 11 on the housing of a clutch unit 18. It will later becomeapparent that the shaft 66 will be rotated from the main differentialgear unit, and for forward drive the end of the shaft 66 will beconnected to rotate with the clutch housing 18 through clutch plates 19,the housing 18 rotating with the vehicle propeller shaft 8|, a portionof which is shown extending from the right hand end of the transmissionhousing in Fig. I. The clutch plates 19 are actuated by oil pressurewhich is fed into the unit through conduit 82, pressure causing plates19 to be forced together, thereby connecting the end of the shaft 66 andthe housing 18. When not held in engagement by oil pressure a spring 15serves to disengage the clutch plates. It is understood that the clutchplates 19 are of conventional construction, wherein .one half the platesare connected to the shaft 66 and the other half or alternate plates areconnected to the housing 18. When it is desired to effect reverse 1drive a band 83 is actuated to stop the rotation roller clutch 86.

of the carrier 14 through the flange 84 and the When the carrier 14 isheld against rotation mechanism later to be described will release theclutch plates 19 and the drive from the shaft 66 will go through gears16, planetary gears 12 and 13, and into the internal gear 11 on theclutch housing 18. On inspection of Fig. 1 it will be apparent that thiswill effect reverse drive and the vehicle propeller shaft 8| will bedriven in the opposite direction from that effected by directconnectionthru clutch plates 1 The operation of the unit so far described will nowbe considered. For this purpose it will be assumed that-some type ofcontrol is available to hold the reaction ring 46 in a position ofmaximum eccentricity and-tovary the amount of this eccentricity tocontrol the gear ratio of the transmission. Starting with the lowestgear ratio available'for starting the car, the engine will rotate thefly wheel 22 since it is directly connected with the crankshaft of theengine, and the action of the cylinder and pistons 24, 26 in thefly-Wheel unit will pump fluid into the hydraulic operated unit aspreviously noted. Since the position of the reaction ring 46 is such asto cause a definite relative rotation between the sleeve 34 and shaft 32when fluid is pumped into the successive cylinder and piston units, thenby such rotation the differential gear 58 connected with the sleeve willbe rotated relative to spider 59. Further, since the wheels of thevehicle are only just beginning to turn the carrier or spider 59 of thedifferential gear unit will be substantially stationary, and thereforethe shaft 32 and the crank 3| which is splined to this carrier will alsobe substantially stationary or just beginning to turn. It is apparenttherefore that when the spider 59 is held against rotation or is movingvery slowly, and when the gear 58 has a maximum turning effort exertedupon it, there will be a gear ratio between the engine and the outputshaft 8| of a maximum amount. However, as the car begins to acceleratethe spider 59 will rotate at a faster rate and there will be a lessdifference between the and 12) which controls the flow of fluid underpressure to the aforementioned cylinder and piston unit I I3.

Further details of the construction of the gov emor are shown best inFig. '1, where it appears I that the driving shaft I01 of thegovernor-isinreality a hollow shaft or sleeve through which a secondshaft H1 is mounted to slide, this shaft I" being connected to thegovernor in such manner as to reflect the speed at which the governor isoperating by the longitudinal position of shaft II'I inside the sleeveI01. The shaft I I1 has an extension II8 which is connected to thecontrol valve H6 through suitable gearing 9, the throttle control shaftI I being also connected to the shaft extension H0 by a lever I2I, andthe movement of both the governor shaft H8 and the throttle controllever I2I being controlled by a spring I22. It is apparent that thisdouble connection of the governor shaft and the throttle control ontothe member which is connected to the control for positioning the yokeIII provides means to change the position of the reaction ring 46 inFig.1, so that the gear ratio of the transmission will be changed inproportion to the combined action of the governor and throttle control.

The governor I09 is constructed in such manner that its action is morepositive with increase in speed. This result is accomplished byprovision of a plurality of arms such as I09a pivoted to swing on apivot at I09!) and so shaped as to provide an end I09c which reactsagainst a conical shaped plate I09e. mounted at the end of each arm. .Itis obvious on consideration of Fig. '1, except for a short initialmovement which breaks the flat surface contact inside the end I090, thatas the speed increases and the weights I09) are thrown outward, the endI090 will slide outward on the inclined surface adjacent thereto and thedistance from end I09c to pivot I092: will decrease because of themovement of the end I000 on conical plate I09e and will thereforeincrease the leverage of the weight I09! since the distance from theweight I09) to pivot I09b remains constant. Therefore, the action of thegovernor will be more positive for the higher speeds because of thegreater leverage alforded.

The valve H6 and its connection-to operate the yoke III is shownindetail in Figs. 11 and 12. It is noted that the valve H6 is made up oftwo sliding valve parts, an outer sleeve I23 and an inner valve memberI24. The outer sleeve I23 is connected to be operated by the governorand throttle control as previously mentionedby a connection effectedthrough the rack I26. The outer housing I21 of the valve IIG has an oilpressure inlet I28 to which fluid under pressure is furnished from thepreviously mentioned pump I04. The pressure inlet I28 connects with thesleeve I23 so that pressure is fed into a slot I29 cut in the side ofthe sleeve and for all positions of the sleeve pressure from this slotis furnished to an annular groove I3I which is cut around the centralportion of the inner valve member I24. However, the opposite side of thesleeve I23 is of such construction as to cover the entire length of theannular groove lllflbut in positions to each side of the groove there;is cut in the sleeve I23 an upper port I32 and arlow'er port'l33.

These ports are so positioned thatwhen the sleeve I23 is moved in eitherdirection relative to the inner valve member I24 the pressure from theinlet I28 and the annular groove I3I will be allowed to enter eitherport I32 or -I33jdepend'- ing upon the direction of the movement of thesleeve. The inner valve member I24 is connected witha shaft I34 on whichthe yoke .III

is mounted, and for instance if the action of the governor and throttlecontrol is to move the sleeve upwards as viewed in Fig. 12, the port I33will be put in communication with the annular groove I3I and allowpressure to enter therethrough and into a'port I36 and into the lowerchamber I31 of the cylinder and piston unit-I I3 throughsuitable-conduit I38. The result of ,this will be to force a piston I39119-- wardly a shown in Fig. 12 and this movement will continue untilthe sleeve I23 and the inner member I24 are again in alignment to cutoil the aforementioned flow of pressure. If the movement of the sleeveI23is in the opposite direction from that above noted or downwardly asviewed in Fig. 12, pressure will be fed into the upper port I32 and intoan upper chamber I through suitable conduits I42 and m.- It'is obviouson inspection of Fig. 12 that this will cause movement in the oppositedirection and allow the yoke III to move downwardly as it ,is

viewed in Fig. 10. For the purpose of allowing discharge of fluid fromcy der I4I when cylinder I31 is receiving pressure an annular groove I35is provided in inner member I24 with drilled opening I35a to a centraloutlet conduit I35b which drains the fluid to the sump. The samemovement of sleeve I23 which connects port I33 with pressure connectsport I32 with the outlet as will be apparent on inspection of Fig. 12.Similar annular groove I 40 and drilled opening Idfla serves as anoutlet for the cylinder I31 when cylinder MI isreceiving fluid underpressure. Y

Considering the action of the valve H6 and its control of the movementof the cylinder and piston unit H3 and the yoke III, it IS apparent thatthe ultimate result is that the yoxe III is caused to move a distancedetermined by the amount of movement imparted to the sleeve I23,following this movement step by step because pressure is-fed to thepiston unit until the inner valve member I24 which reflects the movementof the yoke III becomes again aligned with the sleeve I23.

Reverse mechanism control As previously noted in the description of thegeneral arrangement of the transmission shown in Fig. 1 reverse drive isaccomplished by tightening the band 83 on the flange 84 so that thecarrier 14 which supports the gears 12 and 13 is held stationary. Inorder to produce this tightening of the band 83 the cylinder and pistonmechanism I13 shown in Fig. 15 is used. As will be apparent oninspection of this figure, a piston I14 which is secured to a shaft I16is normally urged in one direction by a spring I11 and for the purposeof urging the shaft I16 against the action of the spring, pressure inletI18 is provided so that fluid under pressure may be admitted to achamber I19 to urge the iston I14 and the shaft I16 in a directionagainst the action of the spring I11. It is this movement of parts abovementioned by the action of the pressure that tightens the band 83previously mentioned. This is ac-. v complished by a lever I6I which isof a shape and .the band in a manner well known in the art formechanisms of this character. Y

Construction of oil pump The detailed construction of the oil pump I04is shown in Figs. 13 and 14 of the drawings. The central housing I46 ofthe pump is substantially cylindrical in shape with flanges at both ofits ends. A plurality of cylinders I41 are formed in the housing andpositioned so as to be equally spaced in a circle about the center ofthe housing as shown in the view, Fig. 14. It also appears in Fig. 14that there are six of these cylinders formed in the housing. The bottomof this housing is covered with a plate I48 as seen in Fig. 13

and this plate covers the bottom end of the cylindrical openings I41.Each cylinder opening is provided with a piston I49 formed with asemispherical upper end and having a drilled out central portion toretain a spring I5I. It will be noted by reference to Fig. 13 that eachof the pistons I49 is normally urged upwardly out of its cylindricalopening I41 by the reaction of the spring on the plate I40 and of thedrilled central opening in the piston. A housing I04 is secured to thetop flange of the lower housing I46 and provides a wall surrounding awobble plate unit I53 which is of such diameter as to rotate upon thetopof the semi-spherical ends of the six pistons I49. The wobble plateunit I53 is pivotally mounted upon a cover plate I54 which is pinned torotate with the pump shaft I56. The pivotal connection for the wobbleplate is shown at I51 in Fig. 13 and the opposite side of the wobbleplate is normally held in a downward position by spring I58- whichreacts between a boss I59 on the covering plate I54 and a projection I6Ion the wobble plate. As the shaft I56 is rotated, it carries with it thecover plate and the wobble plate unit I53 including the spring I58on-the pivot I51 and from an inspection of Fig. 13 it will be apparentthat such rotation will produce successive reciprocation of the sixpiston units I49. The inner end of the shaft I56 is of such shape as toco-act with inlet and outlet passages in the central portion of thehousing I46. As shown in Fig. 13 the inlet to the pump is in the lowercentral portion thereof and is indicated at I62. This inlet openingconnects with the drilled hole I63 in the center of the shaft I56 whichis so positioned as to connect with conduits I64 and I65 to allow inletof fluid to the bottom of cylinders I41 as the shaft rotates. It isunderstood that rotation of shaft I56. will successively allow fluid toenter the bottom of the six cylinders I41, the relative position of theconduit I65 and the inclination of thewobble plate I53 being such thatthe inlet of fluid is timed to occur during the intake stroke of thepiston and cylinder to which fluid is being admitted. Similarly chamberI61 is provided on the opposite side of the end portion of the shaft I56and it also serves as a connection with the bottom portion of thecylindrical openings I41 as the shaft rotates, but in this case contactwith the cylinder opening is effected at the time when the piston is onits downward or outlet stroke.

This action forces the fluid from the cylinders 1 to chamber I61 formedby an opening in the housing and a cut-out portion I68 of the shaft I56.The shaft is also provided witha drilled outlet I69 to an upper chamberHI and this chamber in turn connects directly with the main outlet I12from the pump. It will be apparent from the above description and byreference to Figs. 13 and. 14 that rotation of the shaft I56 will drawfluid into the inlet I62 and cause this fluid to enter the cylinders I41during the upward stroke of the pistons I49 and this fluid be eventuallyforced outwardly through the outlet I12 by the downward stroke of eachof the pistons. V

In the operation of the above described pump the spring I58 controls themaximum pressure which will be maintained in the outlet from the pump.This result is attained because of the fact that when the pressure fromthe outlet exceeds a certain amount determined by the springthe springwill allow the wobble plate I53 to assume a position substantiallyperpendicular to the shaft I56, and it will be evident on inspection ofFig. 13 that in such a position the wobble plate will not causereciprocation of the several pistons I49. An important advantage of thistype of construction is that, regardless of the rate of rotation of thepump shaft I56, the pressure which is generated by the pump will neverbe built up to a greater value than is allowed by the strength of thespring and it is therefore unnecessary to employ safety valves or otherspecial equipment to limit the pressure in the outlet line.

Fluid pressure system Fig. 17 shows, in partially diagrammatic form, theconduit connections between the several fluid pressure operated units.the pump I04 is the source of fluid pressure and a conduit 20! isconnected to the pump outlet. The conduit 20! branches into a conduit202 which leads to control valve II6 previously described and shown inFig. 12 as actuating the piston I39 for varying the eccentricity throughyoke III (Fig. 10). Another branch conduit 203 leads to a manuallycontrolled distributing valve 204, also shown in Fig. 7, as well as Fig.17. The valve 204 has a sliding central member 206 with three annulargrooves 201, 208, 209 out therein. The valve housing has an inlet 2| Ito which conduit 203 connects to furnish fluid under pressure. There aretwo outlets 2I2, 2I3 on the opposite side of the housing, the outlet 2I2leading to the reverse cylinder I19 through a conduit, and the outlet2I3 leading to a collector ring and inlet 82 adjacent clutch 19 (Fig. 1)through a conduit 2I6. Two outlets 2I1, 2! in the valve housing areconnected with the sump. It is apparent on inspection of Fig. 17 andFig. '7 that upward movement of the member 206 of the valve will feedpressure to the reverse cylinder I19 by connection of conduit 203 withconduit 2I4 through inlet 2, annular groove 208, and outlet 2I2. Thesame upward movement will connect clutch operating conduit 216 with thesump and release all pressure therein through opening 2I3, annulargroove 209 and outlet 2I8; Downward movement of the valve member 206reverses the above arrangement and feeds pressure to operate clutch 19and release the reverse cylinder I19.

Another branch 2I9 from conduit 203 leads to the hydraulic motor 31 toassure that some pressure will always be available therein.

It will be apparent that the fluid pressure As shown in Fig. 17.

purpose of illustration, but rather to the scope of the followingclaims.

I claim:

1. In a transmission mechanism, input shaft, K

an output shaft, a differential gear connected to rotate with said inputshaft, a second differential gear connected to rotate with said outputshaft, a differential spider member mounted to rotate between saiddifferential gears, differential pinion gears carried by said spidermember and meshing with said differential gears, afluid displacingmechanism positioned to be actuated by relative rotation between saidinput shaft and said spider member and designed to allow relativerotation in amount proportional to said fluid displacement, a fluidoperated unit carried to rotate with said input shaft having a pluralityof opposed pistons and cylinders movable in proportion to thedisplacement of fluid from said fluid displacing mechanism, a reactionring, ends of said opposed pistons positioned to contact said reactionring, means for adjustably supporting said reaction ring at varyingamounts of eccentricity from the center of rotation of said motor,thereby to vary the displacement of fluid allowed to be made by saidfluid displacing mechanism into said fluid operated unit wherebyrelative movement is allowed between said input shaft and said spidermember to control gear ratio in proportion to the eccentricity of saidreaction ring.

2. In a transmission, an input shaft, an out--- put shaft, a hydraulicdisplacing unit, a hydraulic operated unit, a mechanical gear trainoperating between said input and output shafts to provide variation ingear ratio in proportion to relative rotation between said output andinput shafts, a

' shaft mounted inside said input shaft for connecting said hydraulicdisplacing unit to drive the same from a member of said gear train,fluid conduits in said input shaft connecting said displacing unit withsaid hydraulic operated unit, and a mechanical connection from saidhydraulic operated unit to said gear train whereby torque is exerted bysaid hydraulic motor unit to increase the rotative torque and speed ofsaid output shaft thereby to change the gear ratio.

3. In a transmission mechanism, an input shaft, an output shaft, adifferential gear connected to rotate with said input shaft, a seconddifferential gear connected to rotate with said output shaft, adifierential spider member mounted to rotate between said differentialgears, difierential pinion gears carried by said spider member andmeshing with said differential gears, a hydraulic displacing unitactuated by relative movement between said spider member and said inputshaft, a hydraulic operated motor unit actuated by fluid displaced bysaid hydraulic displacing unit, and a mechanical connection from saidhydraulic operated unit to one of said differential gears whereby torqueis exerted by said hydraulic operated unit to increase the rotativetorque and speed of said output shaft thereby to change the gear ratio.

4. In a transmission, an input shaft, an output shaft, a mechanical geartrain operating between said input and output shafts to providevariation in gear ratio in proportion to relative rotation between saidoutput and input shafts, a hydraulic displacing unit operated inproportion to difference in rotation of said input and output shafts, ahydraulic operated unit rotatable by displacement of said hydraulicdisplacing unit, an adjustable reaction member for said hydraulicoperated unit, and a mechanical connection from said hydraulic operatedunit to said gear train whereby torque is exerted by said hydraulicoperated unit to increase the rotative torque and speed of said outputshaft thereby to change the gear ratio.

5. In a transmission mechanism, an input shaft, an output shaft,adifierential gear connected to rotate with said input shaft, a seconddifferential gear connected to rotate with said output shaft, adifferential spider member mounted to rotate between said differentialgears, differential pinion gears carried bysaid spider member andmeshing with said differential gears, a fluid displacing mechanismpositioned to be actuated by relative rotation between said input shaftand said spider member and designed to allow relative rotation in amountproportional to said fluid displacement, a fluid operated unit havingmembers movable in proportion to the displacement of fluid from saidfluid displacing mechanism, and control means for said fluid operatedunit comprising a reaction ring positioned to contact one of saidmovable members of said fluid operated unit, means for adjustablysupporting said reaction ring in varying amounts of eccentricity fromsaid movable member, thereby to vary the displacement of fluid allowedto be made by said fluid displacing mechanism into said fluid operatedunit whereby relative movement is allowed between said input shaft andsaid spider member to control gear ratio in proportion to theeccentricity of said reaction ring. ROY W. WESTON.

